feat: add SAMR vehicle recall source

[BrownieCoder]

Summary

• add the official SAMR domestic vehicle recall source to the China column
• parse each notice's full title, canonical URL, and publication date from the public list page
• refresh every 30 minutes as a realtime source and include the generated source metadata
• add a focused parser unit test

Why

NewsNow currently has no official automotive safety source. The SAMR recall
list provides timely, publicly accessible notices for vehicle safety issues in
China.

The implementation performs one request to the public list page per refresh;
it does not crawl detail pages or require authentication.

Source: https://www.samrdprc.org.cn/qczh/gnzhqc/

Validation

• pnpm test --run — 41 tests passed
• pnpm exec vite build — production build passed
• lint-staged pre-commit checks passed
• local /api/s?id=samr smoke test returned status: success and 17 current recall notices